题目

The two brothers look so much alike that it is difficult to ______.  A. tell them from           B. tell from them  C. tell apart them           D. tell them apart 答案：D 下列有关电化学装置完全正确的是（ ）ABCD铜的冶炼铁上镀银防止Fe被腐蚀构成铜锌原电池A．AB．BC．CD．D